<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form method="post" action="userServlet">
    用户名: <input type="text" name="userName"> <br>
    <input type="submit" value="校验">
</form>
<link rel="stylesheet" href="static/css/btn.css">
<img src="static/img/img.png">
</body>
</html>